Lambda probes which include a sealing device on the reference air side are well-known. In this type of lambda probe, a section of a sensor element is introduced into the exhaust air stream to be measured while another area of the sensor element is located in a so-called reference air chamber for the purpose of reference. This reference air chamber is formed by one part of the housing of the lambda probe and of the sealing device, the sealing device having the function of sealing the reference air chamber as tightly as possible.
German Published Patent Application No. 195 40 022 describes an arrangement for the sealing of a cable penetration for lambda probes of motor vehicles. The sealing takes place using a bushing which seals a housing of the lambda probe on one side. The electrical contact of the sensor element is established via cables which have an electrically conducting core and an insulating jacket and which penetrate the bushing. The bushing itself is made from glass fiber reinforced Teflon. In order to improve the seal, an O-ring is additionally inserted between the inside wall of the housing and the bushing.
This sealing arrangement is as much in need of improvement as its manufacture is expensive. Furthermore, the use of an insulating jacket for the cables causes problems in relation to a desired hermetic seal, particularly at high temperatures.